Means for protecting the heater in a circulating liquid system



Dec. 21, 1965 5, ox 3,224,675

MEANS FOR PROTECTING THE HEATER IN A CIRCULATING LIQUID SYSTEM Filed July 29. 1957 m P I \JQI 7 9 INVENTOR. E L TON 5. FOX

We 4 M United States Patent ()fifice 3,224,675 Patented Dec. 21, 1965 3,224,675 MEANS FOR PROTECTING THE HEATER IN A CIRCULATING LIQUHD SYSTEM Elton B. Fox, 681 36th St., Richmond 9, Calif. Filed July 29, 1957, Ser. No. 674,666 13 Claims. (Cl. 2378) My invention relates to circulating liquid systems in which the circulating liquid is heated and maintained at desired temperature, and more particularly relates to means for protecting the heater in such a system. For purposes of description, the invention will be illustrated as applied to the circulating system for a swimming pool.

In such a system, the water is conventionally heated by a flash type boiler. Such type of heater usually heats with gas as the fuel, and includes heater tubes or coils through which the liquid to be heated, flows. These tubes are usually of thin wall construction and if insufficient water flows through them during heating, the tubes are apt to get too hot and burn out. On the other hand, if flow becomes too heavy, the tubes become sufiiciently cold to cause condensation of atmospheric moisture thereon and this results in trouble.

Among the objects of my invention are:

(1) To provide novel and improved means for protecting the heater in a circulating liquid system employing a heater of the type having tubes or coils through which the liquid flows;

(2) To provide novel and improved means for protecting a flash boiler against burn out of its tubes or coils when employed in a water system;

(3) To provide novel and improved means for avoiding condensation of atmospheric moisture on the tubes or coils of a water heater while employed in a water system; and

(4) To provide novel and improved means for protecting the heater in a swimming pool water system, against burn out or condensation of atmospheric moisture during heating.

Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawing which depicts such a system embodying the present invention.

Referring to the drawing for details of my invention in its preferred form, the invention is depicted as embodied in a water circulating system for a swimming pool wherein a pump 1 having an associated intake line 3 connected to the pool 5, discharges to a heater or boiler 7 through a connecting line 9, such heater functioning to add heat to the water prior to such water being returned to the pool through a return line 11. The pool, pump, and the heater are thus in series flow connection.

The heater 7 is usually of the flash type wherein the water is caused to flow through tubes or coils mounted in close proximity to a flash type burner which is automatically caused to go on or oil in accordance with the need for adding heat to the water in the pool. No attempt has been made to depict the heat control for such burner inasmuch as it could be conventional and forms no part of the present invention.

To protect the heater against excessive high temperatures, which might be sufficient to prematurely burn out the tubes or coils therein, and to further protect the heater against excessive low temperatures sufficient to cause condensation on the outer surfaces of such tubes or coils, I provide means for maintaining the temperature of the heater within a relatively narrow safe range during heating cycles, by controlling the flow of liquid through the heater in such a manner as to maintain such narrow range of temperature. Such range of temperature may be between and degrees Fahrenheit as measured on the discharge side of the boiler.

Broadly speaking, I accomplish this by providing a bypass connection around the heater and by utilizing a temperature responsive sensing unit in the heater flow path. The flow through the heater may be altered to correct adverse conditions while simultaneously altering the flow through the by-pass connection in the reverse sense.

Specifically, I provide a thermostatically controlled valve assembly 13 having a housing 15 with at least three connecting openings 17, 19 and 21 therein, and connect such valve assembly in the system with a fiow connection 23 from the heater to the housing at one of said openings 17, a by-pass flow connection 25 from a point 27 in the system intermediate the pump 1 and the heater 7, to the valve housing, at a second of said openings 19, the return flow connection 11 to the tank or pool being then connected to the housing at the third opening 21.

Within the valve assembly housing, a valve seat 29 encircles the flow path through the heater-connected opening 17, a valve seat 31 encircles the flow path through the bypass connected opening 19, this latter valve seat being preferably located opposite the first valve seat and in spaced relationship thereto. Disposed in operative relationship to both valve seats is a valve 33 adapted to be shifted in position whereby it may simultaneously enlarge one flow path while restricting the other.

A temperature sensing unit 35 located in the flow path from the heater, preferably by supporting the same in the housing 15, is connected to the valve by suitable coupling 37 for actuating the valve in response to temperature changes at said sensing unit, brought about by any change in temperature of the liquid coming from the heater. With a rise in temperature above a preset value, the sensing unit will expand and move the valve away from the one valve seat to enlarge the flow passage from the heater, the valve at the same time restricting the flow through the by-pass connection 25. The resulting increase in flow through the heater will serve to bring its temperature down to within the desired narrow safe range of operation, while the simultaneous reduction of flow through the by-pass connection will serve to maintain the overall flow and the load on the pump substantially constant.

On the other hand, should the flow through the heater become so great that the temperature of the water tends to drop to the point where condensation of atmosphere moisture will occur on the heater coils, the sensory unit, in contracting, will move the valve in the direction constricting the flow path from the heater while simultaneously enlarging the flow path through the by-pass connection, with the result that, while the over-all flow through the pump will be maintained substantially constant, the flow through the heater will be diminished, thereby enabling the burner to more quickly bring the temperature of such water up to within the narrow safe operating range.

The rapidity with which the system responds to any tendency on the part of the temperature of the heater to swing beyond the limits of the narrow range which is deemed safe, becomes a direct function of the sensitivity of the sensing unit. Sensing units of various types and of high degree of sensitivity are available, but that which I prefer and which has been depicted in the drawing, is one relying upon the heat expansion characteristics of a wax composition for its operation. Such type is depicted in the patent to Dillman, No. 2,548,878, of Apr. 17, 1951.

A minimum flow of liquid through the heater is desirable at all times even during non-heating periods, so that the sensing unit may be exposed at all times to the temperature conditions within the heater as reflected by the liquid within the heater tubes or coils.

This may be accomplished in any of a number of ways which will provide a by-pass flow connection around the valve 33. A rather simple way of realizing this is to provide the valve with a seating flange 41 in which wi l be one or more perforations or notches 43 sutlicient to permit of the desired minimum flow when the valve is seated across the fiow passage from the heater.

From the foregoing description of my invention, it will be apparent that the same fulfills all the objects attributed thereto, and while I have illustrated and described the same in its preferred form and in considerable detail, the same is subject to alteration and modification without departing from the underlying principles involved, and I accordingly do not desire to be limited in my protection to the specific details so illustrated and described except as may be necessitated by the appended claims.

I claim:

1. In a liquid heating system involving a tank, a pump, and heater in series flow connection, said heater being of the type having heater tubes through which the liquid flows, means for protecting said heater against excessive temperatures sufficient to prematurely burn out said tubes or temperatures sufficiently low to cause excessive condensation on the outer surfaces of said tubes, said means including a flow connection by-passing said heater, valve assembly means adapted to alter the resistance to flow of liquid through said heater while simultaneously altering the flow resistance through said by-pass flow connection in the reverse sense, a temperature sensing unit in the flow path through said heater between said heater and said by-pass connection, for actuating said valve assembly means in response to temperature changes at said sensing unit.

2, In a liquid heating system involving a tank, a pump, and heater in series flow connection, said heater being of the type having heater tubes through which the liquid flows, means for protecting said heater against excessive temperatures sufficient to prematurely burn out said tubes or temperatures sufliciently low to cause excessive condensation on the outer surfaces of said tubes, said means including a How connection by-passing said heater, valve assembly means adapted to alter the resistance to flow of liquid through said heater while simultaneously altering the flow resistance through said by-pass flow connection in the reverse sense, a temperature sensing unit in said valve assembly means in the flow path through said heater between said heater and said by-pass connection, for actuating said valve assembly means in response to temperature changes at said sensing unit.

3. In a liquid heating system involving a tank, a pump, and heater in series flow connection, said heater being of the type having heater tubes through which the liquid flows, means for protecting said heater against excessive temperatures sufiicient to prematurely burn out said tubes, or temperatures sufficiently low to cause excessive condensation on the outer surfaces of said tubes, said means including a thermostatically controlled valve assembly having a housing with at least three openings therein, a flow connection from said heater to said housing at one of said openings, a by-pass flow connection from a point in said system intermediate said pump and said heater to said valve assembly housing at a second of said openings, and a flow connection from said housing at the third of said openings to said tank, valve means in said housing adapted to alter the resistance to flow of liquid through said heater connected opening while simultaneously altering the resistance to flow of liquid through said by-pass connected opening in the reverse sense, a temperature sensing unit in the flow path through said heater to said valve means, and means coupling said sensing unit to said valve for actuating said valve in response to temperature changes at said sensing unit.

4. In a liquid heating system involving a tank, a pump, and heater in series fiow connection, said heater being of the type having heater tubes through which the liquid flows, means for protecting said heater against excessive temperatures sufiicient to prematurely burn out said tubes, or temperatures sufficiently low to cause excessive condensation on the outer surfaces of said tubes, said means including a thermostatically controlled valve assembly having a housing with at least three openings there n, a flow connection from said heater to said housing at one of said openings, at by-pass flow connection from a point in said system intermediate said pump and said heater to said valve assembly housing at a second of said openings, and a How connection from said housing at the third of said openings to said tank, valve means in said housing adapted to alter the resistance to flow of liquid through said heater connected opening while simultaneously altering the resistance to How of liquid through said by-pass connected opening in the reverse sense, a temperature sensing unit in said housing in the flow path from said heater to said valve means, and means coupling said sensing unit to said valve means for actuating said valve means in response to temperature changes at said sensing unit.

5. In a liquid heating system involving a tank, a pump, and heater in series flow connection, said heater being of the type having heater tubes through which the liquid flows, means for protecting said heater against excessive temperatures sufficient to prematurely burn out said tubes, or temperatures sufiiciently low to cause excessive condensation on the outer surfaces of said tubes, said means including a thermostatically controlled valve assembly having a housing with at least three openings therein, a flow connection from said heater to said housing at one of said openings, a by-pass flow connection from a point in said system intermediate said pump and said heater to said valve assembly having at a second of said openings, and a fiow connection from said housing at the third of said openings to said tank, valve means in said housing adapted to alter the resistance to flow of liquids through said heater connected opening while simultaneously a tering the resistance to flow of liquids through said by-pass connected opening in the reverse sense, a temperature sensing unit in said housing in the flow path from said heater to said valve means, means coupling said sensing unit to said valve means for actuating said valve means in response to temperature changes at said sensing unit, and means providing a minimum flow of liquid by said sensing unit at all times in the operation of said system.

6. In a liquid heating system involving a tank, a pump, and heater in series flow connection, said heater being of the type having heater tubes through which the liquid flows, means for protecting said heater against excessive temperatures sufficient to prematurely burn out said tubes, or temperatures sutficiently low to cause excessive condensation on the outer surfaces of said tubes, said means including a thermostatically controlled valve assembly having a housing with at least three openings therein, a flow connection from said heater to said housing at one of said openings, a by-pass flow connection from a point in said system intermediate said pump and said heater to said valve assembly housing at a second of said openings, and a flow connection from said housing at the third of said openings to said tank, a valve seat encircling the flow path through said heater connected opening, a valve seat encircling the flow path through said by-pass connected opening and located opposite said first valve seat in spaced relationship thereto, valve means in said housing intermediate said two valve seats and adapted to alter the resistance to flow of liquid through said heater connected opening while simultaneously altering the resistance to fiow of liquid through said by-pass connected opening in' the reverse sense, a temperature sensing unit in said housing in the flow path from said heater to said valve means, means coupling said sensing unit to said valve means for actuating said valve means in response to temperature changes at said sensing unit, and means providing a minimum flow of liquid by said sensing unit at all times in the operation of said system.

7. A valve assembly adapted to simultaneously alter in opposite sense, the resistance to flow of liquid in parallel paths, comprising a housing having at least three openings therein, two of said openings being located opposite each other, a valve seat bounding each of said openings within said housing, valve means in said housing intermediate said two valve seats and adapted, in response to movement between said valve seats, to alter the resistance to flow of liquid through one of said openings while simultaneously altering the resistance to flow of liquid through the opposite opening in the reverse sense, a temperature sensing unit entirely within said housing in the flow path of liquid through one of said openings, and means mechanically coupling said temperature sensing unit to said valve.

8. A valve assembly adapted to simultaneously alter in opposite sense, the resistance to flow of liquid in parallel paths, comprising a housing having at least three openings therein, two of said openings being located opposite each other, a valve seat bounding each of said openings within said housing, valve means in said housing intermediate said two valve seats and adapted, in response to movement between said valve seats, to alter the resistance to flow of liquid through one of said openings while simultaneously altering the resistance to flow of liquid through the opposite opening in the reverse sense, a temperature sensing unit entirely within said housing in the flow path of liquid through one of said oepnings, means mechanically coupling said temperature sensing unit to said valve, and means providing for a minimum flow of liquid by said sensing unit associated opening with said valve engaging the valve seat associated with said opening.

9. A flow governor system, comprising; a governor including a casing provided with two inlets and an outlet; means communicating with one of said inlets for delivering liquid to said one inlet and for heating said liquid during the course of its flow to said one inlet; means communicating with the other of said inlets in by-passing relation with said heating means for delivering liquid to said other inlet without exposing it to said heating means; valve means in said casing controlling flow through each of said inlets, said valve means permitting at least a restricted flow through said one inlet at all times and being normally partially open to permit flow through said other inlet; and a thermostatic drive element in said one inlet to further open said valve means with respect to said one inlet in response to an increased temperature of liquid delivered to said one inlet.

10. A flow governor system, comprising; a governor including a casing provided with two inlets and an outlet; means communicating with one of said inlets for delivering liquid to said one inlet and for heating said liquid during the course of its flow to said one inlet; means communicating with the other of said inlets in by-passing relation with said heating means for delivering liquid to said other inlet without exposing it to said heating means; valve means in said casing controlling flow through each of said inlets, said valve means permitting at least a restricted flow through said one inlet at all times and being normally partially open to permit flow through said other inlet; and a thermostatic drive element in said one inlet to further open said valve means with respect to said one inlet in response to an increased temperature of liquid delivered to said one inlet, said drive member simultaneously moving said valve means toward closed portion with respect to said other inlet.

11. A flow governor system, comprising; a governor including a casing provided with two inlets and an outlet; means communicating with one of said inlets for delivering liquid to said one inlet and for heating said liquid during the course of its flow to said one inlet; means communicating with the other of said inlets in by-passing relation with said heating means for delivering liquid to said inlet without exposing it to said heating means; valve seats positioned in said casing to control flow through the respective inlets; a valve element positioned in said casing to cooperate with one valve seat to partially close off flow through said one inlet when said valve element is in closed position with respect to said one valve seat without restricting flow through said other inlet; and a thermostatic drive element connected with said valve element and moving the same off of said one valve seat in response to an increased temperature of liquid delivered to said one inlet to permit increased flow through said one inlet, said valve element being thereby moved toward the other of said valve seats to obstruct flow from said other inlet.

12. A flow governor system, comprising; a governor including a casing provided with two inlets and an outlet; means communicating with one of said inlets for delivering liquid to said one inlet and for heating said liquid during the course of its flow to said one inlet; means communicating with the other of said inlets in by-passing relation with said heating means for delivering liquid to said other inlet without exposing it to said heating means; a valve seat positioned in said casing and disposed across the path of flow through said one inlet; a second valve seat disposed across the path of flow through said other inlet; a valve element mounted in said casing and movable between positions where its opposite ends engage the respective valve seats; a thermostatic drive element responsive to increased temperature of flow through said one inlet to move said valve element away from said one valve seat and toward said other valve seat to simultaneously adjust the relative openings of the respective valves; and means for permitting a restricted flow of liquid through said governor from said one inlet when said valve element is in engagement with said firstmentioned valve seat.

13. A governor for controlling discharge temperature of liquid from a heat exchanger of the type having an inlet for liquid from said heat exchanger and an inlet from a by-pass around said heat exchanger, and an outlet, comprising; a valve housing a plurality of spaced port means in the walls of said housing, certain of said port means communicating with said inlet from the heat exchanger, other of said port means communicating with said inlet from the by-pass, while still other of said port means communicate with said outlet, a valve element movable within said housing from one extreme position in which the port means which communicates with the inlet from the by-pass is fully opened and the port means which communicates with the inlet from the heat exchanger would otherwise be fully closed, to another extreme position in which the port means which communicates with the inlet from the by-pass is fully closed and the port means which communicates with the inlet from the heat exchanger is fully opened, one of said closure means being provided with an opening in communication with said inlet from the heat exchanger, whereby liquid from the heat exchanger is permitted to pass through said valve in all positions of said movable valve element and a thermostatic drive element in said inlet from the heat exchanger responsive to increased temperature of flow therethrough and operatively connected to said valve element, for opening the port means in communication with the inlet from the heat exchanger.

References Cited by the Examiner UNITED STATES PATENTS 8 FOREIGN PATENTS 79,030 3/1955 Denmark.

OTHER REFERENCES Sarco Water Blender: received in US. Patent Office Giesler 23634.5 August 20, 1937, published by Sarco, Inc., 188 Madison Giesler -23 634.5 Ave., New York, NY.

Jorgensen et a1. 236 -34.5

L 237 8 EDWARD J. MICHAEL, Primary Examiner.

wqtzsteon FREDERICK L, MATTESON, 111., Examiner. Relmuller 23693 

9. A FLOW GOVERNOR SYSTEM, COMPRISING; A GOVERNOR INCLUDING A CASING PROVIDED WITH TWO INLETS AND AND OUTLET; MEANS COMMUNICATING WITH ONE OF SAID INLET FOR DELIVERING LIQUID TO SAID ONE INLET AND FOR HEATING SAID LIQUID DURING THE COURSE OF ITS FLOW TO SAID ONE INLET; MEANS COMMUNICATING WITH THE OTHER OF SAID INLETS IN BY-PASSING RELATION WITH SAID HEATING MEANS FOR DELIVERING LIQUID TO SAID OTHER INLET WITHOUT EXPOSING IT TO SAID HEATING MEANS; VALVE MEANS IN SAID CASING CONTROLLING FLOW THROUGH EACH OF SAID INLETS, SAID VALVE MEANS PERMITTING AT LEAST A RESTRICTED FLOW THROUGH SAID ONE INLET AT ALL TIMES AND BEING NORMALLY PARTIALLY OPEN TO PERMIT FLOW THROUGH SAID OTHER INLET; AND A THERMOSTATIC DRIVE ELEMENT IN SAID ONE INLET TO FURTHER OPEN SAID VALVE MEANS WITH RESPECT TO SAID ONE INLET IN RESPONSE TO AN INCREASED TEMPERATURE OF LIQUID DELIVERED TO SAID ONE INLET. 